A headlight for a vehicle, such as a motorcycle, may include a housing that opens toward front side and an outer lens that covers the opening (refer to Patent Literature 1). The housing and the outer lens form a light chamber that houses a lamp unit having a projection lens and a light source. The lamp unit and the housing have an extension disposed therebetween. The whole of the lamp unit is made movable to adjust an optical axis. The extension is provided to make an optical axis adjuster and other components in the housing hardly visible when the inside of the headlight is looked from the outside through the outer lens, thereby improving the appearance.